Give examples on heteropolysaccharides?

Glycosaminoglycans (GAG) proteins forming proteoglycans) rich in glucosamine and galactosamines. Hyaluronan is a polymer of N-acytelglucosamine and glucuronic acids Chondroitin sulfate (in extracellular matrix)is a polymer of N-acetylgalactosamine and glucuronic acid) keratane sulfate is made of D-Galactose and N-acetylglucosamine occurs in cartilage and cornea